There are various secret menus hidden in the Android OS. Here are some of them (thanks to [askvg.com](http://www.askvg.com/google-android-hidden-secret-codes/)):
| Code | Description |
|:-------------------:|:---------------|
| `*#*#checkin#*#*` | Forces the system to check for updated apps or a pending system update (found that one [here](http://www.androidspin.com/2010/05/22/breaking-news-google-begins-roll-out-of-android-2-2-to-the-nexus-one/comment-page-1/#comment-17428) first) |
| `*#*#info#*#*` | Shows various informations about GSM network, CDMA, WLAN, battery, etc.; also allows you to change a few |
| `*#*#rst0#*#*` | Will do a **FACTORY DATA RESET** after a confirmation |
| `*2767*full#` | Will do a **FACTORY FORMAT** - :warning: **WITHOUT CONFIRMATION** :warning: Be careful! |
| `*#*#34971539#*#*` | Get information about camera (**NEVER try to update the camera firmware!!**) |
| `*#*#7594#*#*` | Lets you change turn on/off the *Power off* menu |
| `*#*#create*all*663282*#*#*` | opens a screen where you can copy your internal media files to SD |
| `*#*#197328640#*#*` | Service tests, you can also change some settings there |